sscanf() in a loop

[beatlea]

Hello,
Is there any way of reading words from a string containg a few words separated by white spaces using a loop? I don't know how many argumets the user will input. I wanted to do it like this:

for(i=0;i<wordCounter;i++)
{
  sscanf(input,"%s",argument[i]);
}

But this keeps reading in the first word from the string.

[Narue]

You can use the %n conversion specifier to find out how many characters were read and adjust the source string accordingly:

#include <stdio.h>

int main( void )
{
  const char *src = "this is a test";
  char word[5];
  int n;

  while ( sscanf ( src, "%4s%n", word, &n ) == 1 ) {
    puts ( word );
    src += n;
  }

  return 0;
}

Note that the usual guideline of using the number of conversion specifiers to determine what value scanf should return doesn't apply here. %n doesn't add to the number of conversions, which is why the loop uses 1 instead of 2 to mark success.

[beatlea]

Sorry, but I don't understand this code :( Why do you have to use puts(word) after reading in to word with sscanf? And what does += do?

[Narue]

>Sorry, but I don't understand this code
Gone are the days when rookies would take a new piece of code and run off to dissect it. :(

>Why do you have to use puts(word) after reading in to word with sscanf?
Because it's generally a better example if you can see that it's working. :icon_rolleyes:

>And what does += do?
It does exactly what your book on C tells you it does: adds the value on the right to the value on the left.

[beatlea]

Yes, I did try it and all I got was a compiler error. It doesn't like src += n;

error: invalid operands to binary +

[Narue]

>Yes, I did try it and all I got was a compiler error.
Post the exact code you tried then, because you messed it up somehow. Also mention which compiler and OS you're using.

[Salem]

Sounds like bad copying on your part, replacing a pointer with an array.